Comment 21 for bug 231628

I'm going to answer those tricky questions based on what I think as an end user:

>If you browse to a different site and then hit the Back button, should we update the zoom or preserve the previous zoom?

Ideally preserve the previous zoom. i.e. the same page loaded in the same tab should get the same zoom level it got the first time, unless the page has been manually reloaded (either by entering the URL or hitting the Reload button).

>Should we preserve the zoom across sessions (i.e. hook it into the session
store)?

Ideally, yes, but not that important.

>Which zoom level is the site-specific one (the last one you picked, some
previous selection, some separately-selected value)?

The last one you picked. Let's say you open multiple windows with different pages from the same site (something I do a lot with Wikipedia, by the way), the site-specific zoom level should be the one set last.

>If a page in a background tab reloads itself, do we update the zoom? What if
it redirects the browser to another site with an updated pref?

The zoom level for a page should be updated only if the page has been reloaded manually, not if it has been reloaded programmatically or as a result of using the Back/Forward button.

If you get redirected to a page from another site with an updated site-specific zoom level, the page should get displayed with the new zoom level.